VEHICLE-MOUNTED POWER SUPPLY DEVICE AND VEHICLE COMPRISING POWER SUPPLY DEVICE
A power supply device for a vehicle connectable in parallel to a lead-acid battery of 12 V, comprises a battery block including a plurality of secondary batteries capable of charging and discharging, a circuit board having an electric circuit configured to control the charging and discharging of the battery block, and a storage case for storing the battery block and the circuit board. The battery block is configured to connect an N number (N being a natural number) of nickel hydride batteries as the secondary batteries in series.
The present invention is related to a vehicle-mounted power supply device and a vehicle comprising the power supply device, for example, a battery system for a vehicle where a lead-acid battery and a sub-battery are connected in parallel, and a vehicle incorporating this battery system.
BACKGROUND ARTA conventional vehicle incorporates a lead-acid battery having a nominal voltage 12V of a lead-acid storage battery, and a large vehicle incorporates a battery having a nominal voltage 24 V where 2 pieces of the lead-acid batteries of 12 V are connected in series. The lead-acid battery is charged by an alternator of the vehicle, and supplies power to electric equipment devices or a starter motor. The lead-acid battery has a small discharging resistance, but has a large charging resistance, and then it is difficult to efficiently charge it. In order to improve this problem and enlarge the battery capacity (Ah) with respect to volume and weight, the battery system for a vehicle where the lead-acid battery and the lithium ion secondary battery are connected in parallel, is developed. (refer to patent literature 1)
CITATION LIST Patent Literature
- Patent Literature 1: Japanese Laid-Open Patent Publication No. 2007-46508
However, as the voltage of the lithium ion secondary battery cell is normally 3.6 V, and even in the series connection, for example, it has 10.8 V of 3 series connection, 14.4 V of 4 series connection, and any one coincides with 12 V, and then it by itself cannot be connected to the lead-acid battery of 12 V. Therefore, a voltage converting circuit which increases or decreases the total voltage of the sub-battery including the lithium ion secondary batteries, is necessary, and it complicates a circuit, and it increases cost. In addition, a loss occurs by the voltage conversion, and such a loss is consumed as heat, and then the temperature of the sub-battery is increased. Especially, the battery generates heat by charging and discharging, and as the amount of current increases, the amount of heat generation also increases. The heat generation of the battery influences the adjacent electric circuit and also the life of the battery in itself. In order to stably use the sub-battery during a long time, it is desirable that heat radiation is improved. The heat loss is not preferable from the view point of heat radiation.
The present disclosure is developed for the purpose of solving such problem. One non-limiting and explanatory embodiment provides a power supply device for a vehicle and the vehicle incorporating the power supply device where it is connectable to a lead-acid battery without voltage converting.
A power supply device for a vehicle of the present disclosure connectable in parallel to a lead-acid battery of 12 V, comprises a battery block including a plurality of secondary batteries capable of charging and discharging, a circuit board having an electric circuit configured to control the charging and discharging of the battery block, and a storage case for storing the battery block and the circuit board, and the battery block is configured to connect an N number (N being a natural number) of nickel hydride batteries as the secondary batteries in series. Accordingly, by connecting the nickel hydride batteries of the nominal voltage 1.2 V in series, the required total voltage can be easily adjusted without voltage converting.
In the power supply device for a vehicle of the present disclosure, the battery block is configured to connect 10×n (n being a smaller natural number than N) pieces of the nickel hydride batteries in series. Accordingly, the total voltage of the battery block can be multiples of 12 V, and then the battery block can be connected in parallel to the lead-acid battery of 12 V or 24 V
In the power supply device for a vehicle of the present disclosure, the battery block is configured to connect 10 pieces of the nickel hydride batteries in series. Accordingly, the total voltage of the battery block is 12 V, and then it can be connected to the lead-acid battery of 12 V without voltage converting of increasing voltage or decreasing voltage.
In the power supply device for a vehicle of the present disclosure, a thermal insulation dividing wall divides the storage case into a storage space of the battery block and a storage space of the circuit board. Accordingly, the circuit board can be protected from heat generation of the battery block by the thermal insulation dividing wall.
In the power supply device for a vehicle of the present disclosure, a cooling air passage is formed to send a cooling air to a battery storage space divided by the dividing wall, and further an air passage opening is formed at the outer surface, and is connected to the cooling air passage with consecutive space. Accordingly, by the cooling air introduced from the air passage opening, the battery block disposed at the cooling air passage can efficiently radiate heat.
In the power supply device for a vehicle of the present disclosure, each of the nickel hydride batteries has a cylindrical outer case, and a covering portion having a curved surface along surfaces of the plurality of the cylindrical nickel hydride batteries is formed in the storage case. Accordingly, the secondary battery of the cylindrical shape has a large surface area to enhance heat radiation. Also the covering portion has the curved surface along the cylindrical shape, and then has a large surface area to enhance heat radiation in the same way.
In the power supply device for a vehicle of the present disclosure, each of the nickel hydride batteries is held in a horizontal posture in the storage case. Accordingly, even though water is stored by condensed water or the like in the storage case, short circuit of the positive and negative terminals of the total voltage can be prevented, and then safety can be enhanced.
In the power supply device for a vehicle of the present disclosure, the power supply device is capable of being installed in a vehicle having idling stop function, and both of the lead-acid battery and the power supply device are capable of being charged with power of regenerative power generation of the vehicle.
A vehicle having the power supply device of the present disclosure comprises an engine for driving, a radiator for cooling the engine for driving, and a cooling fan for forcibly blowing air to the radiator, and the cooling air passage is disposed in an air passage of the cooling fan.
A vehicle having the power supply device of the present disclosure comprises an engine for driving, and an alternator driven by the engine, or a regenerative braking of the vehicle, and the power supply device is charged by the alternator at the regenerative braking, and the vehicle has idle stop function.
In a vehicle having the power supply device of the present disclosure, the power supply device is disposed in an engine room.
Hereinafter, the embodiment of the present invention will be described referring to drawings. However, the following embodiments illustrate a power supply device for a vehicle and the vehicle having the power supply device which are aimed at embodying the technological concept of the present invention, and the present invention is not limited to the power supply device for a vehicle and the vehicle having the power supply device described below. In particular, as long as specific descriptions are not provided, it is not intended that the claims be limited to sizes, materials, shapes, and relative arrangements of constitutional members described in the embodiments, which are mere descriptive examples. It is noted that the magnitude or positional relation of the members illustrated in each diagram is sometimes grandiloquently represented, in order to clarify the description. Furthermore, in the description below, identical names and reference numbers represent identical or homogeneous members, and detailed descriptions are appropriately omitted. Moreover, mode may be applied where each element constituting the present invention constitutes a plurality of elements with the use of the same member, thereby serving the plurality of elements with the use of one member, or, in contrast, mode may be realized where a function of the one member is shared by a plurality of members. Also, a portion of examples and the content described in the embodiments can be applied to other examples and another embodiment.
Embodiment 1A perspective view showing a power supply device 100 related to one embodiment 1 of the present invention is shown in
The storage case 30 has a rectangular shapes or a rectangular parallelepiped shape in the external appearance. The storage case 30 is preferably made of material excellent in insulation properties, for example, a resin. The plurality of the secondary batteries 1 and the circuit board 20 are stored in the storage case 30.
The pair of the output terminals 36 projects from the upper surface of the storage case 30. The output terminals 36 are configured to have a positive side output terminal 36+ connected to the positive side and a negative side output terminal 36− connected to the negative side in the total voltage of the battery block 10. Further, as shown in the vertical sectional view of
A gas exhaust hole 37 is opened at the upper surface of the storage case 30. In the case where the secondary battery 1 exhausts a gas, the gas is exhausted through the hole 37 in order not to excessively increase the pressure in the storage case 30. It is preferable that the gas exhaust hole 37 is coupled to a duct which safely exhausts the exhausted gas outside the vehicle.
The battery block 10 has a negative side connecting terminal 12 located at the lower surface side inside the storage case 30, and the positive side connecting terminal 14 located at the upper surface side inside the storage case 30. The positive side output terminal 36− is located at the upper surface side of the storage case 30, and is connected to the negative side connecting terminal 12 located at the lower surface side of the storage case 30 by a negative side lead board 50−. Further, the positive side output terminal 36+ is connected to the positive side connecting terminal 14 by the positive side lead board 50+. The positive side lead board 50+ is shorter than the negative side lead board 50−. In addition, the negative side connecting terminal 12 of the battery block 10 is grounded.
(Secondary Battery 1)The secondary battery 1 is capable of storing electric power, and the secondary battery cell can be suitably used. The nickel hydride battery can be suitably used as the secondary battery cell. Especially, as the power source voltage of the nickel hydride battery is 1.2 V, series connection of 10 pieces of the nickel hydride battery has 12 V, and is suitable for being connected to the lead-acid battery PB of the power source voltage of 12 V. In the example of
Further, as the secondary battery group 2 is configured to connect 2 pieces of the secondary batteries 1 in the elongated direction, there is no secondary battery between the 2 pieces of the secondary batteries 1. As one end surface in each of the 2 pieces of the secondary batteries 1 faces outside without facing other secondary batteries, heat radiation from this end surface is obtained. In addition, heat radiation can be more improved such that this surface is disposed so as to face a side surface of the storage case 30.
In the example shown in
Additionally, in a battery storage space BS where the battery block 10 is disposed in the storage case 30, as shown in
In the above example, in the battery block, the secondary batteries are arranged in the same plane, but the secondary batteries can be arranged in plural layers. For example, as shown in the power supply device 100B of the schematic sectional view of
The secondary batteries are directly exposed in the cooling air passage. Other than this, as shown in
The covering portion 32 covers the surfaces in the secondary batteries 1 facing the cooling air passage 31B. Namely, in the sectional view of
Further, it is preferable that a forcible cooling mechanism is provided so as to forcibly blow a cooling air in the cooling air passage. Such a forcible cooling mechanism is newly added, or the existing members are also used as the forcible cooling mechanism, and it is preferable form the view point in simplifying the structure or reducing the manufacturing cost. For example, in the power supply device for a vehicle, a cooling fan for a radiator can be used. An example where the power supply device is set in an engine room of the vehicle is shown in
The circuit board 20 is disposed between the battery block 10 and the main surface of the storage case 30. This circuit board 20 includes an electric circuit for monitoring charging and discharging of the secondary batteries 1. Further, the circuit board 20 may include a safety protection circuit for cutting off a current when an abnormal state in each of the secondary batteries 1 is determined. Such an abnormal state in each of the secondary batteries 1 is monitored based on a current, a voltage, and a temperature.
The switching portion 25 is connected to the output of the battery block 10, and switches the ON/OFF of the output. In the example shown in the circuit diagram of
As shown in the sectional view of
As shown in the sectional view of
The surroundings of the circuit board 20 can be covered. In the example of
As shown in the vertical sectional view of
On the contrast, in the present embodiment, as each of the secondary batteries is disposed in a laterally disposed posture, in the case where water is stored in the storage case 30, the number of the secondary batteries covered with water can be restricted in the minimum. Namely, as each of the secondary battery groups 2 constituting the battery block 10 is arranged in the vertical direction in a horizontal posture, only both ends of the secondary battery group located at the bottom surface are covered with water. In this state, even though a short circuit occurs, as the difference of the electric potentials is by 2 pieces of the secondary batteries, and for example, in the case of using the nickel hydride battery of 1.2 V, the difference of the electric potentials is 2.4 V, and then a short circuit current is small. Especially, in the case of the power supply device using the nickel hydride batteries, it is necessary that a gas exhausted from the nickel hydride battery at the time of over-charge is exhausted outside, and the gas exhaust hole is opened. Therefore, the storage case cannot use an airtight structure. As the result, it is difficult that intrusion of water into the storage case is stopped. However, as mentioned above, since each of the secondary batteries is disposed in a laterally disposed posture in the storage case having a hole for gas exhaust, damage by being covered with water is suppressed widely, and also the gas exhausted from the nickel hydride battery can be safely exhausted outside the storage case.
Further, the output terminals 36 are connected to the total voltage of the battery block 10, but as the secondary battery located at the bottom surface side is the negative side, safety can be improved. Namely, as the negative side is connected to the chassis ground, the difference of the electric potentials in the short circuit of this portion is smaller than that in the short circuit of the positive side.
(First Lead Board 51)In the secondary battery group 2 in each of the plural layers, the end edges of the secondary battery groups 3 vertically arranged are connected by first lead boards 51. The first lead boards 51 connect the secondary battery groups 2 to each other in the shortest distance. Such lead boards are made of a metal board having an excellent conductivity
The total voltage of the battery block 10 is outputted from the output terminals 36 through the positive side lead board 50+ and the negative side lead board 50−. In the example shown in the sectional view of
Even though the water level at which water intrudes in the storage case 30 is increased, only the number of the secondary battery group is increased corresponding to the increased water level. As long as the battery block 20 is not completely covered with water, short circuit by the total voltage does not occur. Thus, the merit that short circuit current is suppressed corresponding to the water level, is obtained.
As the positive side lead board 50+ is disposed at the highest layer, namely at the highest position of the battery block 10, even though water intrudes in the storage case 30, the possibility that short circuit occurs at this position is comparatively low, and then safety can be improved. Additionally, as the output terminals 36 are provided at the upper surface of the storage case 30, namely the highest position of the storage case 30, the possibility that the output terminals 36 are short-circuited, can be decreased in the same way. Similarly, the bus bars 54 are provided at the high position in the storage case 30, the risk that this portion is covered with water can be decreased, and then reliability and safety can be improved.
Moreover, the positive side total voltage is located at the highest layer of the battery block 10, the distance from the positive side output terminal 36+ is short, and then the length of the positive side lead board 50+ which connects these, can be short. Thus, as the exposed area of the positive side lead board 50+ becomes small, the risk that short circuit occurs can be decreased.
Here, in order to prevent the negative side lead board 50− from unintentionally contacting each of the first lead boards 51, it is desirable that an insulating member such as an insulating sheet is disposed between these first lead boards 51 and the negative side lead board 50−.
In the above example, the example where the secondary batteries are disposed in the horizontal posture in the storage case, is explained. However, the plurality of the cylindrical secondary batteries can be also held in a vertical posture in the storage case. The power supply device 100C related to such a modified example is shown in a perspective view of
The example where the above power supply device 100 is connected to the battery system for a vehicle, is shown in
The lead-acid battery PB has a nominal voltage 12 V by connecting 6 cells in series. Here, the present invention is not limited to the nominal voltage 12 V of the lead-acid battery. The nominal voltage 24 V is made by the series connection in 2 pieces of the lead-acid batteries, and the nominal voltage 36 V is made by the series connection in 3 pieces of the lead-acid batteries, and the nominal voltage 48 V is made by the series connection in 4 pieces of the lead-acid batteries. The conventional electric equipment is designed to operate at the power source voltage 12 V, and the vehicle incorporating the lead-acid battery 24 V to 48 V incorporates the electric equipment operating at this voltage.
The sub-battery connected in parallel can improve efficiency of charging and discharging, and can prevent degradation of the lead-acid battery. The sub-battery has the same voltage as the lead-acid battery by being connected in parallel to the lead-acid battery. In this state, current balance in charging and discharging between the sub-battery and the lead-acid battery PB, namely suitability is important. When the suitability is bad, only the lead-acid battery or only the sub-battery is charged, or only the lead-acid battery or the sub-battery is discharged. Thus, even though both are connected in parallel, efficiency of charging and discharging cannot be improved, or the life of the lead-acid battery cannot be effectively prolonged.
The suitability of the lead-acid battery PB and the sub-battery is realized to control characteristics of open-circuit voltage vs depth of discharge of the sub-battery. The characteristics of open-circuit voltage vs depth of discharge of the sub-battery is, for example, adjusted by the amount of zinc or the like added to the positive electrode in the nickel hydride battery.
The power supply device 100 is disposed vertically next to the lead-acid battery, and is stored in the engine room of the vehicle. As the power supply device 100 is used in the high temperature environment, in order to obtain high temperature durability, the electrolyte of the nickel hydride battery as the secondary battery 2, contains the at least one type of compound selected from a tungsten compound, a molybdenum compound, and a niobium compound. This configuration can provide the power supply device 100 which has durability in the case of installation in the engine room in addition to a high output (low resistance).
The above battery system can improve a fuel efficiency even in the vehicle where the alternator 6 driven by the engine 96 charges without regenerative braking. It is a reason why the power supply device 100 as the sub-battery can be charged with power at most 8 times more than that of the lead-acid battery PB. The alternator 6 of the vehicle charges the lead-acid battery with a constant voltage to prevent degradation, and in order to keep the supplied voltage to the electric equipment 5 to a constant value, the output voltage of the alternator 6 is stabilized to a constant voltage of about 14 V. Therefore, a current with which the alternator 6 charges the lead-acid battery PB is small, and the lead-acid battery PB is not charged with large current. Therefore, the alternator 6 of the output current 100 A is installed in the vehicle, but the alternator 6 do not charge the lead-acid battery with 100 A, and the alternator 6 supplies power to the electric equipment 5 with large current. As the alternator 6 charges the battery system with large current, a fuel efficiency of the vehicle can be improved. It is a reason why the alternator 6 is driven in the range of a high generation efficiency and also the engine 96 can be driven in the range of a low fuel consumption rate. The alternator 6 is low in a generation efficiency by a low load, and the engine 96 is high in a fuel consumption rate by a low load.
Further, the battery system for a vehicle using this power supply device 100 charges not only the lead-acid battery PB but also the power supply device 100 to protect the lead-acid battery PB from large current charging. In a state where the alternator 6 does not charge, not only the lead-acid battery PB but also the charged power supply device 100 supplies power to the electric equipment 5, and then the lead-acid battery is prevented from large current charge or over discharge, and the life can be prolonged.
INDUSTRIAL APPLICABILITYA power supply device for a vehicle and the vehicle having the power supply device related to the present invention can be suitably used a battery for an electric equipment in the vehicle or an auxiliary battery. Especially, in the vehicle which has an idling stop function to charge the lead-acid battery by regenerative braking, the load of the lead-acid battery can be reduced.
REFERENCE MARKS IN THE DRAWINGS
- 100, 100B, 100C: power supply device
- 1: secondary battery
- 2: secondary battery group
- 5: electric equipment device
- 6: alternator
- 10, 10A, 10B: battery block
- 12: negative side connecting terminal
- 14: positive side connecting terminal
- 20: circuit board
- 22: dividing wall
- 25: switching portion
- 26: circuit surrounding board
- 30, 30B, 30C: storage case
- 31, 31B, 31C: cooling air passage
- 32: covering portion
- 34, 34a, 34b: air passage opening portion
- 36: output terminal 36+: positive side output terminal 36−: negative side output terminal
- 37: gas exhaust hole
- 50: lead wire
- 50+: positive side lead board
- 50−: negative side lead board
- 51: first lead board
- 54: bus bar
- 96: engine
- 97: wheel
- 98: cooling fan
- 99: radiator
- PB: lead-acid battery
- HG: heat insulation space
- BS: battery storage space
Claims
1. A power supply device for a vehicle connectable in parallel to a lead-acid battery of 12 V, comprising:
- a battery block including a plurality of secondary batteries capable of charging and discharging;
- a circuit board having an electric circuit configured to control the charging and discharging of the battery block; and
- a storage case for storing the battery block and the circuit board,
- wherein the battery block is configured to connect an N number (N being a natural number) of nickel hydride batteries as the secondary batteries in series.
2. The power supply device for a vehicle according to claim 1,
- wherein the battery block is configured to connect 10×n (n being a smaller natural number than N) pieces of the nickel hydride batteries in series.
3. The power supply device for a vehicle according to claim 2,
- wherein the battery block is configured to connect 10 pieces of the nickel hydride batteries in series.
4. The power supply device for a vehicle according to claim 1,
- wherein a thermal insulation dividing wall divides the storage case into a storage space of the battery block and a storage space of the circuit board.
5. The power supply device for a vehicle according to claim 4,
- wherein a cooling air passage is formed to send a cooling air to a battery storage space divided by the dividing wall, and
- further an air passage opening is formed at the outer surface, and is connected to the cooling air passage with consecutive space.
6. The power supply device for a vehicle according to claim 1,
- wherein each of the nickel hydride batteries has a cylindrical outer case, and a covering portion having a curved surface along surfaces of the plurality of the cylindrical nickel hydride batteries is formed in the storage case.
7. The power supply device for a vehicle according to any claim 1,
- wherein each of the nickel hydride batteries is held in a horizontal posture in the storage case.
8. The power supply device for a vehicle according to claim 1,
- wherein the power supply device is capable of being installed in a vehicle having idling stop function, and both of the lead-acid battery and the power supply device are capable of being charged with power of regenerative power generation of the vehicle.
9. A vehicle having the power supply device according to claim 5, comprising:
- an engine for driving;
- a radiator for cooling the engine for driving; and
- a cooling fan for forcibly blowing air to the radiator,
- wherein the cooling air passage is disposed in an air passage of the cooling fan.
10. A vehicle having the power supply device according to claim 1, comprising:
- an engine for driving; and
- an alternator driven by the engine, or a regenerative braking of the vehicle,
- wherein the power supply device is charged by the alternator at the regenerative braking, and the vehicle has idle stop function.
11. A vehicle having the power supply device according to claim 1,
- wherein the power supply device is disposed in an engine room.
Type: Application
Filed: Oct 24, 2013
Publication Date: Dec 3, 2015
Inventors: HIDEKI SAKATA (Hyogo), KAORU NAKAJIMA (Hyogo), AKINOBU TSUNESADA (Hyogo)
Application Number: 14/435,602